Not trying to do anything more than hit coyotes killing my chickens so please bear that in mind.

From my back porch, I am about 6'-8' above the elevation of the pastures around me.

In a perfectly flat environment, 556 should rise about 1.5"-1" if zeroed at 50, when shot at 100 yards

So from the elevated position, what would be the effect?

Is that working AGAINST the rise at 100? Net zero?

I am too mentally challenged to spit out an automatic answer so I am asking the crew. What do you think?

I'm not following your thought process....

AR-15 iron sights are approximately 2.7" higher than the barrel's bore. Scopes can be a little higher or lower depending on ring's height.

Your line of sight is straight, the arc of the bullet in flight is not.

If I zero 1.25" to 1.5" high at 100 yards my .223 rifles will be dead on at 200. At 50 yards I should be a little lower than the aiming point because the bullet's slight hasn't made up the 2.7" bore v. sights height difference.

Iron sights work the same way, provided you use a "Navy hold", meaning covering the target with the front sight, splitting a bullseye target along a horizontal line.

I use a six o'clock hold with iron sights, otherwise known as "a pumpkin on a fence post". This zero has me printing on target approximately 2.5 moa to 3.0 moa above my point of aim.  This allows me to see the target I'm aiming at because it's directly above the front sight post, not being obscured by it.  

The only time you need to consider elevation inputs is when the shot angle is in the mountains or other high elevation platforms where the angle up or down is relatively extreme and there is increased distance to overcome.

A nine foot rise in the prairie does not a mountain make.  

The effect would be inconsequential.


a² + b² = c²


If the distance from your elevated position (8 feet higher than the target) to the target is 100 yards, the bullet will impact the target as if it had traveled 99.68 yards (the actual horizontal distance to the target.)



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Ok cool. Thanks. I knew i was asking the right people

If you want to see for yourself how negligible it is, enter the info into a ballistics calculator. This one is pretty basic but easy to use:
http://www.shooterscalculator.com/ballistic-trajectory-chart.php

From my experience, shooting up or down hill, at any significant distance, you need to aim a couple inches high.  What's the maths?  I'm too dumb for that....Just know to hold over a bit if shooting up or down mountains.  We have one 100 yard range that is significantly up hill; I can see the top of the building from the 100 yard target.  When I zero a rifle at that range, the elevation is off a bit when I go to a level range.

No effect at all. Even if you were shooting nearly straight up or straight down. Time of flight is too low for angle to have any effect at all.

shooting up or down hill will make the round strike high relative to the point of aim.  With your cartridge, height above ground and range, fergeddaboudit.  Just shoot.

If you really want to know you can simply try it out one day yourself. Put a target where you think the coyotes might be and see how it hits. That takes all the guess work out of it for you.

A bit more intuitive way to think about it is as follows:  How far is it if the target were straight away.  That is, if you were shooting at something in a tree (vertical cliff), or from a tree, how far away is the base of the tree (cliff) on level ground. That is the distance you figure out your hold over.

https://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

For drop, only the component of distance perpendicular to gravity matters, so the horizontal distance between you and the target.

If you range straightline distance, get an angle cosine meter, multiply.

If you are shooting straight up or straight down it's definitely going to affect POI.  Shooting at steep angles reduces the horizontal distance to the target which will usually result in POI being higher no matter if you are shooting uphill or downhill.

If you can shoot a coyote off your back porch, you can also place a target on a piece of cardboard and a stick at 100yds, and shoot at it off your back porch to test it yourself.  One or two rounds is all you need to confirm.  This is not rocket science or am I missing something in your translation......

Some people just want to do it, others want to know how it got done. Michael Jordan was the greatest player, but not a good coach/GM. Steve Kerr was a decent player, but a great coach.

It's a good ballistics question with a practical application.